Kaldellis, Anthony and Marion Kruse: The Field Armies of the East Roman Empire. Cambridge:Cambridge University Press, 2023.

Anthony Kaldellis is Professor of Byzantine Studies at the Department of Classics at the University of Chicago. His research interests comprise Byzantine history, literature, and culture, in particular, the reception of classical thought and literature, intellectual history as well as the relationship between Hellenism and Christianity.

Marion Kruse is Assistant Professor at the Department of Classics at the University of Cincinnati. He specializes in late antique and Byzantine literature and history, with a particular focus on the literary and cultural transformations of the Eastern Roman Empire during the fourth to seventh centuries. His other areas of study include Byzantine historiography, classical reception in late antiquity, the development of Christian rhetoric, and the literary representation of power and authority in Byzantium

Their book presents a new perspective on the military administration of the armies of the Eastern Roman Empire between the reigns of Julian (361–363) and Herakleios (610–641). The aim is to provide a narrative of this period that does not rely on the Notitia Dignitatum for the entire time span between 395 and 630, as previous scholars have done.

In the first chapter, The High Command from Julian to Theodosius I (361–395) (pp. 1–22), the authors analyse the structure of the Eastern Roman military from Emperor Julian’s unsuccessful Persian campaign to the death of Theodosius I in 395. Kaldellis and Kruse underscore significant innovations attributed to Theodosius I, including modifications in magisterial commands and the establishment of specific military roles. The chapter highlights the evolving nature of the military hierarchy during this period, thereby challenging previously assumed static models.

In the second chapter, The Late Emergence of the Eastern Notitia System (395–450), (pp. 23–47), Kaldellis and Kruse discuss the challenges of aligning the military and political history of the early fifth century with the administrative system presented in the Notitia Dignitatum. They suggest that the Notitia system may have developed in the 440s, after a period of gradual remilitarization in the east during the 420s. This would suggest the need to reconsider the traditional use of the Notitia Dignitatum for understanding military organization in this period; Kaldellis and Kruse propose a significantly shorter timespan for which the document serves as a reliable source.

In the third chapter, The “Classic” Phase of the Eastern Field Armies (450–506) (pp.48–66), the authors examine the organizational structures, leadership dynamics, and strategic deployments that were characteristic of the Eastern Roman military during this period. This analysis offers valuable insights into how the Eastern Roman Empire adapted its military strategies in response to both evolving external threats and internal challenges.

In the final chapter, The Dispersal and Decline of the Eastern Field Armies (506–630) (pp. 67–91), the authors explore various factors contributing to this decline, including administrative changes, limited resources, and emerging military threats. They also examine the impact of these challenges on the Eastern Roman Empire’s capacity to project military power and maintain territorial integrity during this transitional period.

In addition to the main analysis, the volume includes four appendices that add insight into specific topics connected to the Eastern Roman military, and present useful data on which the authors base their analysis.

Appendix 1, The Roman High Command at Adrianople (378), contains an analysis of the structure and composition of the Roman high command during the Battle of Adrianople, which was a decisive turning point in the history of the Eastern Roman Empire.

Appendix 2, Magistri militum under Theodosius I (379–395), investigates the role and significance of the magistri militum, the highest military commanders, under the reign of Emperor Theodosius I.

Appendix 3, A Revised Fasti of the Eastern Praesental Generals (MMPs), contains a revised list of Eastern Roman praesental generals, providing a detailed overview of the most important military leaders and their terms of office.

Appendix 4, The Date of the Notitia Dignitatum: Oriens, examines the dating of the Notitia Dignitatum, particularly the part relating to the eastern portion of the empire.

“The Field Armies of the East Roman Empire” is an interesting approach towards the military history of the Eastern Roman Empire. Kaldellis’s and Kruse’s detailed analysis makes the book a useful resource for historians focusing on the military during the Early Byzantine period. The perspective on the military administration of the Eastern Roman Empire provides new insights into the Notitia Dignitatum and its proposed timeframe. While the authors’ arguments may not always be entirely convincing, it encourages a critical examination of the source material.